Patent Literature 1 discloses a five-axis vertical machining center, as shown in FIG. 1. This prior art machining center includes a bed 13 as a base, a column 15 mounted on the bed 13, a rotary table 35 arranged on a moving body 27 which moves left and right on the bed 13, a spindle head 21 supporting a spindle 25, and a saddle 17 supporting the spindle head 21 so as to be vertically movable in the Z-axis direction on the left side face of the column 15. A pair of rails 29a and 29b are provided in the bed 13, and the moving body 27 is provided so as to be capable of reciprocating in the lateral direction on the bed 13 along the rails 29a and 29b. At least a part of the moving body 27 can enter a tunnel portion 15c of the column 15.
As shown in FIG. 2, the moving body 27 includes a pair of supports 27a and 27b and is formed in a substantially U-shape. A cradle 33 is rotatably supported by the supports 27a and 27b of the moving body 27 through pivot shafts 31a and 31b. A rotary table 35 on which the workpiece is attached is mounted on the rotary table 35. When machining the workpiece fixed to the rotary table 35, the moving body 27 naturally accumulates swarf in region S in FIG. 2, and there is a problem with swarf dischargeability. Furthermore, in the prior art, since it is necessary that a swarf outlet be provided in the front side of the bed, when swarf is collected and cleaned, the swarf outlet is spaced away from the deposition location of the swarf, requiring additional time and effort.
Patent Literatures 2 and 3 disclose an invention in which a trough for the discharge of swarf is provided below a workpiece table. Since the linear feed axis drive mechanism of the table is present in the trough under the workpiece table, structures such as a table cradle on which the workpiece table is mounted are present in the discharge area, hindering the discharge of swarf, resulting in swarf accumulation leading to poor dischargeability of swarf. Furthermore, Patent Literature 4 discloses a general-purpose machine tool in which a channel-shaped cut chip space is provided under a workpiece table. In this prior art, as a cantilevered tilt table is used, the rigidity of the tilt shaft rotating body is reduced due to the cantilevered structure and the workpiece is inclined such that workpiece falls down in the direction of the column, and the workpiece cannot be tilted toward the operator. Thus, the accessibility of the operator to the workpiece and the table is poor during swarf collection and cleaning.